I’m not sure what the controversy is, seems like it’s an excellent shoe that can be used for 5k - marathon.
In a nutshell :
Some peoples think it is excellent (because fast, mostly for heel strikers)
some others think it is not (because unstable, mostly for heel striker)
Fact is it is fast AND unstable. So it is usable or not for any distance depending your stride and the way you use it.
Personally :
using it heel striking : it destroyed my posterior tibialis and medial side of the knee
using it mid-foot strike : it is OK, but drop is too high. I prefer 5mm drop high cushion shoes
So, excellent for some (at least at the beginning), not that good for others.
Yeah I’m a little bit undecided. The more I run in it, the more I like it. I’m a forefoot striker. The heel does feel weird and unstable, but the shoe is fast and comfortable. It’s an excellent shoe, overhyped possibly. Is it revolutionary? Are there other shoes out there than are light, fast and cushioned? That’s not rhetorical, curious to see if there are? I did get some Hoka Tracers (1st model) which could be considered a rival shoe (?) but they’re horrible to run in and have now been designated to gardening duties.
Light, fast and cushioned, for a forefoot striker ?
VF ok in this case (low injury risk), as FlyKnit and Turbo (if you like high drop - around 10mm)
Reebok Run Fast (8mm drop I think)
If you prefer moderate drop (around 5mm) :
Skechers Razor 3
Skechers Ride 7
NB Beacon
Saucony Kinvara 10 (come soon, serious reviews already available such as RTR)